Retinal cell biology

Retinal cell biology is the key to understanding how the retina works and how certain conditions such as retinopathies or treatments such as laser photocoagulation affect its ability to function. Much of this work is done on a microscopic scale using retinal cells from laboratory animal models or human eyes from autopsies. Scientists look at experimental therapies and their impact on the retina at the cellular level. They can provide high-resolution imaging of how these cellular changes affect visual outcomes. 

K. Hosoya and M. Tomi. Advances in the cell biology of transport via the inner blood-retinal barrier Establishment of cell lines and transport functions. Biol. Pharm. Bull. 28 1-8 (2005). 

Achenbach, S., Liu, Q. and Pierce E.A. (2004) The RPl gene and protein in photoreceptor biology. In Photoreceptor cell biology and inherited retinal degenerations. D.S. Williams, ed. (Singapore World Scientific Publishing Co. Pte. Ltd.), pp. 223-257. 

Packer, Ed. (Academic Press, New York. 1982) pp 763-815. Review of biosynthetic process D. S. Pape rm aster. B. G. Schneider in Cell Biology of the Eye, D. McDevitt, Ed. (Academic Press, New York, 1982) p 475. The photoreceptor activity of visual pigments is due to a carotenoid chromophore, a stereospecific isomer of retinal or 3 -dehydroretinal, 4.4. v., bound as a protonated Schjff base to a lysine moiety in the opsin portion of the molecule A. R. Osenoff, R. 

Studies with taurine-deficient cats have provided a new approach to the study of the cell biology of photoreceptor cells. The mechanism by which retinal taurine-deficiency leads to photoreceptor cell death remains to be defined. The close correlation of retinal taurine deficiency with peak-to-peak ERG amplitudes in taurine-deficient cats suggests that taurine deficiency may have some effect on the ionic fluxes of Na" " and K involved in the generation of the ERG. Since the generation of the ERG depends on hyperpolarization of photoreceptor cells and depolarization of Mtiller cells, it is possible th t taur. ne deficiency has led to abnormal ionic concentrations Na and K ) in photoreceptor and MUller cells. This possibility is currently under investigation. 

Kodoma, R. and Eguchi, G.(1994) The loss of gap junctional cell-to-cell communication is coupled with dedifferentiation of retinal pigmented epithelial cells in the course of transdifferentiation into the lens. International Journal of Developmental Biology 38... 

Many imines play vital roles in biological systems. A key molecule in the chemistry of vision is the highly conjugated imine rhodopsin, which is synthesized in the rod cells of the eye from 11-cis-retinal (the molecule introducing Chapter 21) and a 1° amine in the protein opsin. 

There are many retinal diseases for which currently no effective treatment exists. The potential usefulness of rednal transplantation as a heatment option can be explored once the knowledge of the parameters determining the immunologic rejection of allogeneic retinal hansplant and biologic mechanisms of cells transplanted into subretinal space are better known. 

A number of microcarrier systems have been estabhshed with primary and secondary cells from birds and mammals, permanent cell lines from fish and mammals as well as diploid human cells (Reuveny, 1985). A further possibility is the mass production of cells with the retention of differentiation potential, as can be seen with bone cells (Sautier et aL, 1992) and human retinal pigment epithelial cells (Kuriyama et aL, 1992). In addition to the widely used continuous cell lines for the production of biologicals, freshly harvested cells such as endothelial cells have been applied for the production of endothelium-derived relaxing factor (Bing et aL, 1991). 

Vitamin A and its derivatives retinal and retinoic acid have many essential biological roles in such processes as vision, regulation of cell proliferation and differentiation, and as morphogenetic agents during embryonic... 

Two assays were developed that measure the potency of the FGF-4 transgene carried by Ads FGF-4. In the first case, a one-step growth-promotion assay is conducted on normal, human retinal pigment epithelial cells (ARPE-19). The assay measures metabolic activity (Alamar blue dye metabolism) following infection of ARPE-19 cells with a serial dilution of the virus. The increase in metabohc achvity was measured in relation to a mock-infected control. This increase correlates with FGF-4 produchon determined by an FGF-4 ELISA, increased de-novo DNA synthesis measured by BrdU incorporation, and an increase in cell number. This procedure is therefore an appropriate in-vitro efficacy measure, indicating that the FGF-4 transgene product is biologically active. 

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